Set-off mechanism for printing-presses



(No Model.) I a Sheets-Sheet 1.

J.BROOKS. SET-OFF MECHANISM FOR PRINTING PRESSES.

No. 423,660 Patented Mar.'18,. 1890.

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3 b e e h s 5 b e e h vNb 3 S K 0 O R B 1 MW. d 0 M 0 W SET-OFF MECHANISM FOR PRINTING PRBSSES.

Patented Mar. 18, 1890.

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UNITED STATES PATENT OFFICE.

JOHN BROOKS, OF PLAINFIELD, NEYV JERSEY.

SET-OFF MECHANISM FOR PRINTING-PRESSES.

SPECIFICATION forming part of Letters Patent No. 423,660, dated March 18, 1890.

Application filed Jul 11, 1889. Serial No, 317,201. (No model.)

To all whom it may concern.-

Be itknown that I, JOHN BROOKS, a citizen of the United States, residing at Plainfield, in the county of Union and State of New Jerknown as offset may be prevented, greatly adding to the neatness of the completed work.

To attain the desired end my invention consists, essentially, in a sheet or strip of felt or equivalent material stretched across the press in close proximity to the impression-cylinder, and provided with means for supplying moderate quantities of an ink-repelling liquid such as oil-which is drawn by capillary attraction through the felt and distributed on the surface of the cylinder. This felt is arranged to impinge against the face of the impression-cylinder as it revolves, acting as a distributer to prevent the ink being deposited by the freshly-printed sheets, which have contact with the cylinder succeeding each said distributing operation. The felt may be arranged to strike the face of a small intermediate depositing-roller in lieu of having direct contact with the impression-cylinder, which depositing-roller is arranged to press against and revolve with a second or distributingroller mounted in swinging bearin gs, in order that it may approach or retreat from the portion of the impression-cylinder touched by the inked sheet and away from said cylinder during theremainder of its revolution or during a succeeding revolution, all of which will be hereinafter fully described, and subsequently pointed out in the claims. In the accompanying drawings, in which similar characters of reference indicate corresponding parts, Figure 1 is a side elevation, partly in section, showing the application of my invention to an impression-cylinder of a printing-press; Fig. 2, a side elevation showinder, the shaft 2 whereof is provided with a gear 3, meshing with a gear 4 upon a stud 5. To the hub of. the gear 4 a cam 6 is secured to rotate therewith. 10 is the sheet of felt or other liquid absorbing. medium, which is clamped between the surfaces of the plates 11 12, extending transversely the width of the cylinder 1, and which constitutes the feeder. One of the plates 11 12 is fulcrumed upon a transverse rock-shaft 13, and this shaft 13 bears a rock-arm 8, having an anti-friction roller 7, which bears upon the periphery of the cam 6,'and by means of the latter the edge of the felt 10 opposite the impression-cylinder is thereby caused to advance or retract into or out of contact therewith at intervals determined by the proportion of the gears 3 4. In the present illustration the gears 3 4 are proportioned one to two, respectively, so that the cylinder 1, in carrying the paper at each second revolution, will receive the contact of the felt at each alternate revolution.

Referring now to Figs. 2, 3, and 4, the gear 4 is adapted to transmit motion to a second gear 15, which revolves upon the stud 14 and bears the cam 6 upon its hub in a convenient location to engage with the rock-arm 8. The rock-arm S in this instance is employed to rock a shaft 16, which bears near each end a gear 17. The gears 17 engage with mutilated gears or sectors 18, which are loose on the shaft 19 of the depositing-roller 20. The sectors 18 have arms in which adjustable journals 21 for the shaft 22 of the distributing-roller 23 are located. In' this form of the apparatus the vibration given to the rock-arm 8 is imparted through the instrumentality of the gears 17 and sectors 18, fulcrumed upon the shaft 19, to give an advance and retreating motion to the distributing-roller 23 into and out of contact with the impression-cylinder 1 at intervals between the passing of the paper, While the felt 10 has constant contact with the roll 20. A rotary motion is also imparted to the rollers 20 23 by'means of a gear 25 upon the shaft of the impression-cylinder. The surface speed of the rolls 2O 23 should be equal to the surface speed of the fixed to the shaft 22, with its distributingroller 23, is continuously rotated in the proper direction, whether in contact .or out of contact with the surface 'of the cylinder. The distrlbuting-roll 23 is faced with plush or equivalent material to effect even distribution, and is made to impinge constantly with greater or less pressure upon the solid surface of the depositing-roll 20 by means of setscrews 40 of the adjustable journal-boxes 21. The clamping-plates 11 12, containing the felt, are hung upon'shaft-studs 41 42, which are clamped by means of set-screws 43 in brackets 44 to hold'the edge of the felt against the roll 20 with-a proper degree of permanent contact.

One of the platessuch as 11 in Figs. 2 and 3 or 12 in F1g. 1is provided with hooks 45, which fit over the flattened ends of the shaft studs 41. 42 or the flattened portions of the shaft 13, as the case may be. The feeder is thereby readily lifted off for any obvious purpose.

The clamping-plates 11 12 are beveled at their upper edges to form a receiving trough or groove for the liquid, the ends of such trough or groove being closed. The liquid may be supplied thereto by any suitable means or appliances. I have illustrated in Fig. 1 the employment of a trough 51 containmg the liquid and into which the upper edge of the felt is extended,'so as to overhanginto 1t and convey only such quantities of liquid as will be drawn by capillary attraction. The set-screws 52 are employed to compress the felt to any desired degree, regulating the absorbing and conducting capacity of the same.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is i 1 The combination, with the impressioncyllnder' of a printing-press, of a set-off roller rotating at an equal surface speed therewith,

and mechanism whereby the set-off roller is automatically moved into or out of contact with the impression-cylinder at definite intervals of the latters rotation.

2 The combination, with the impressioncylinder of a printing-press, of a liquid feeder of absorbent material, a rotary depositingroll having permanent contact therewith, and a rotary distributing-roll having permanent contact with the depositing-roll and intermittent contact with the imp'ression-cylinder.

3. The combination, in a printing-machine, of an impression-cylinder, a cam rotated in definite relation to the rotation of the impression-cylinder, a cam-operated rock-arm, a liquid feeder, substantially as specified, a depositing-rolljournaled in stationary-bearings, a distributing-roll journaled in swinging bearings fulcrumed on the axis of the depositing-roll, a toothed gear sector or sectors on said swinging bearings concentric with the said axis, and a toothed gear or gears fixed to the rock-arm shaft engaging with the sector or sectors. 7

4. The combination, in a printing-machine,

ofan impression-cylinder, a liquid-feeder,

substantially as described, a depositing-roll journaled in stationary bearings, a distributing-roll'journaled in swinging bearings fulcruined on the axis of the depositing-roll, intermeshing gears fixed to the shafts of the respective rolls, and atrain of gearing whereby rotation is imparted from a shaft of the machine to the said distributing-roll at a sur-' face speed equal to the surface speed of the impression-cylinder.

' 5. The herein-described set-off feeder, composed of a strip of felt or other absorbent material located parallel with a rotary cylindric depositing-surface, said strip having adjustable clamping-plates wherein it is confined and its absorbing capacity regulated, as specified. 1

6. In a set-off feeder for printing-presses, the combination ofa rotary cylinder presenting a depositing-surface, a felt or other capillary feeder capable of contact with said surface, adjustable clamping-plates wherein said feeder is regulated, as specified, and a liquid receptacle 0r reservoir having communication with the portion of the feeder on opposite sides of the clamping-plates from that portion in contact with said cylinder.

'7. In a set-off feeder for printing-presses, 1 V 

